Yes, we need it asap. Use this semantic versioning concept https://semver.org/ . We have to be able to diffrentiate between version of the whole api, or only some minor changes in a one method.

Yes please

It would also be great if there was a way we could version the API which included different variations of ContentTypes. That way we can make small adjustments to Content-Types, or completely change them and they would still remain working for those requesting the old API version.